The present disclosure relates generally to identifying a network path including network proxies.
Connection tracing is used in a network to identify problem areas and provide detailed information about the network. A connection trace may be used to determine why connections to a given server might be poor, and can often identify the location of problems in cases of instability or other malfunction. TraceRoute is an example of a tool that is used to trace the route of a packet over each hop from a client to a remote host by reporting all router addresses therebetween.
Conventional route tracing utilities such as TraceRoute often do not detect all nodes in a network path. For example, Application-Oriented Networking (AON) uses Web Cache Communication Protocol (WCCP) for traffic redirection to AON nodes (client proxy and server proxy). The proxy terminates a TCP (Transmission Control Protocol) connection received from a client and initiates a new TCP connection to a server. Since the proxy intercepts the message in the path to the server, the proxy can also route an application message to another proxy before the message is sent to the server. This redirection results in traffic passing through a different path than direct client to server communication. Conventional route tracing messages (e.g., TraceRoute, ICMP echo, ping) are not intercepted and redirected to the proxy and therefore follow a different path than what is actually followed by application messages. Proxies located within a communication path are therefore not identified. This also results in application messages reporting much longer latency than observed by conventional route tracing messages, due to additional processing and interception by a proxy. Also, if RSVP (ReSerVation Protocol) or other protocol is used to reserve end-to-end bandwidth from client to server, bandwidth guarantees calculated based on a direct client to server path are not valid if the actual communication path follows a different path due to redirection to a proxy.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.